The subject matter disclosed herein relates to extracting heart motion and cycle information from ultrasound based data, such as an echocardiogram.
Physicians may use a variety of non-invasive techniques to obtain patient cardiac information. Such cardiac information may include time signals that may be used to understand the function of a patient's heart, such as signals that may be used to characterize cardiac cycles. By way of example, signals such as a phonocardiogram (which records heart sounds, similarly to what may be heard through a stethoscope) and an electrocardiogram (i.e., an ECG, which records electrical activity through electrodes positioned on the patient) may provide timing information relevant to cardiac events of interest. Pressure and volume signals may also be obtained, but often require invasive approaches to acquire. These signals have a range of applications, from heart-rate (HR) estimation through diagnosis of pathologies.
Another modality that is increasingly pervasive in cardiac analysis is the echocardiogram, which employs an ultrasound scanner to view the heart. Echocardiogram frames make it relatively easy for healthcare providers to observe, in a noninvasive manner, the heart's anatomy and mechanical function, and qualitatively inspect its contractility, valve dynamics, volume, and so forth.
Despite the many benefits of the echocardiogram, its two-dimensional (2D)-spatial nature makes the assessment of time-related information, such as heart rate and/or the duration of different cardiac phases, less direct. When searching for the exact frame that corresponds to the end of systole, for instance, a physician might scroll through an echocardiogram frame sequence until visually identifying the image or frame when the displayed ventricles are at their minimum volume, which may be time consuming and imprecise. For this reason, it is common to augment the display of echocardiograms with a concurrently displayed electrocardiogram (ECG). This helps physicians to readily obtain the heart rate and to navigate to key frames of the echocardiogram corresponding to a given cardiac phase or electrical event based on the concurrently displayed ECG.
However, there are various situations in which it is typically not possible or convenient to attach ECG electrodes to a patient. For example, this may be true in primary care contexts and in emergency medical contexts, where patient evaluation and/or treatment may be time-sensitive, and thus poorly suited to the laborious electrode placement process typical of ECG acquisition. In these situations, the benefits provided by the concurrent display of the ECG are lost.